In the case of such cross-sectionally deformed hoses which have wall thicknesses which are adapted in accordance with the functioning principle and are intended for the uniformly metered discharge, or the uniform extraction by suction, of liquids or gases over long lengths by way of outlet locations which are arranged lengthwise at certain distances apart, possible categories are "the admission/extraction of air" and "the admission/extraction of water" with the special criteria of "uniform large-surface-area treatment".
In the case of the already known hoses for the metered discharge of gases or liquids, the outlet quantity at the individual outlet locations depends on the internal pressure at the site where they are arranged. The feed-in pressure provided at one hose end drops sharply as the hose length increases (due to friction and branching losses). Along the hose, this results in normally large differences in outlet quantities at the openings, with the result that, for this reason, only short hose lengths are used if there is a need for a relatively uniform liquid or gas discharge per meter.
The uniform discharge is also adversely affected if mechanical drilling in plastics produces burrs in the bore. In the case of a change in pressure, these burrs are forced into the openings again. This results in outlet openings of different sizes, through which, both in the pressureless state and in the pressurized state, the discharge of uniform quantities at each outlet location is not possible.